TITLE:
Analysis of Watershed Attributes for Water Resources Management Using GIS: The Case of Chelekot Micro-Watershed, Tigray, Ethiopia
AUTHORS:
Tesfaye Gebre, Tigist Kibru, Samuale Tesfaye, Gebeyehu Taye
KEYWORDS:
GIS, Morphometric Analysis, Watershed, Drainage Frequency, Drainage Density, Chelekot, Ethiopia
JOURNAL NAME:
Journal of Geographic Information System,
Vol.7 No.2,
April
15,
2015
ABSTRACT: This study identified the
importance of watershed attributes for water resource management using ArcGIS
software, ASTER DEM and satellite images for the Chelekot micro-watershed,
Tigray, Ethiopia. The study also evaluate the different hydrological parameters
which are significant for the water resource management within the
micro-watershed and finds the alternative solutions for water harvesting in the
study area through the introduction of suitable soil and water conservation
structures based on the finding. Principal watershed attributes including
drainage pattern, topographic parameters, land use types, and soil types were
evaluated and interpreted for the study micro-watershed. ArcGIS software was
used for the computation, delineation of the boundary and morphometric analysis
of the micro-watershed using topographical maps and ASTER DEM data. Results
indicate that the micro-watershed has classified as a dendritic pattern with
stream orders ranging from first to fifth order. The micro-watershed has
homogeneity in texture and lack of structural control of surface flow. The
drainage density is medium which indicates the area contains soils with medium infiltration
rates and moderate relief. Drainage texture, stream frequency and the form
factor of the micro-watershed are 4.1, 1.7 and 0.4 respectively. The
bifurcation ratio of the micro-watershed ranges from 1 to 4.5 and the
elongation ratio is 0.7 which reveals that the micro-watershed belongs to the
less elongated shaped micro-watershed category. The mean bifurcation ratio of
the whole micro-watershed is 3.3 indicating that the drainage pattern is not
greatly influenced by geological structures. The micro-watershed land covers
includes: cultivated land (75.8%), settlement and open land (10.5%), shrubs and
plantation (13.2%), and water body (0.4%). The major soil types are Vertisol
(58%), Camisole (32%), Regosol (9.5%) and Luvisol (0.7%). The textural classes
are clay (5%), silty clay (22%), clay loam (17%), sandy loam (21%) and loam
(35%) based on the soil textural map of the micro-watershed. Our results
revealed that using GIS and ASTER DEM data based watershed morphometric
analysis and hydrological evaluation at watershed scale is more applied and
precise compared to other available techniques.